1. Field of the Invention
The present invention relates, for example, to a communication terminal apparatus such as a mobile telephone terminal, to a head set apparatus carrying out a wireless communication with the communication terminal apparatus and to a communication system constituted by these apparatuses.
2. Description of the Related Art
In recent years, a mobile telephone terminal which is one of communication terminal apparatuses a user always taking along in possession has a trend such that various functions other than wireless telephone functions of primary functions are built-in so as to contain multi functions.
For example, there exists such a terminal in which a camera function carrying out a filming of a still picture and a moving picture, a recording and reproducing function of music data, a viewing and listening function of television broadcast or the like is built-in.
In addition, there has been developed a mobile telephone terminal in which a function as a non-contacting IC card which has been prevailing rapidly in recent years is built-in. This non-contacting IC card is utilized as a boarding ticket of transport facilities, a membership card, an employee ID card, a card for price settlement means at a shop or the like where an authentication process is carried out by performing wireless communication between adjacent reader and writer, so that it is easy-to-use as compared with a magnetic card or the like. It should be noted in a case when an IC card function unit is mounted in a mobile terminal that the IC card function unit is not always necessarily to have a card type shape.
And now, it is preferable for the mobile telephone terminal having multi functions in this manner to be carried out with a process in order to secure some kind or another security for preventing various functions provided in the terminal from being abused when the terminal is lost. In particular, in case of a terminal installed with an IC card function unit, there is a possibility that personal information stored as the IC card function is read out unjustly or unjust settlement or the like utilizing the IC card function is carried out, so that the necessity for a function for preventing the unjust use thereof is high. There are descriptions, for example, in patent documents 1 and 2 that a wireless card which forms a pair with respect to the mobile telephone terminal is prepared and authentication request is wireless-transmitted periodically from that wireless card such that the functions of mobile telephone terminal is made to be restricted in a case when collation with respect to the authentication request cannot be taken.
[Patent Document 1] Jap. laid-open patent publication No. 2001-352579
[patent document 2] Jap. laid-open patent publication No. 2001-358827
However, it is necessary for the apparatus described in the patent document 1 and 2 to prepare a wireless card for exclusive use for utilizing the security system of the mobile communication terminal. For example, it is possible to enjoy hands-free conversations pleasantly by using a head set which carries out short distance wireless communication with a mobile telephone terminal, but the management becomes troublesome for a user in a case when a wireless key for security is added thereto, because management objective devices such as hanging a wireless card down around the neck by using a neck strap in addition to putting on a head set on a head portion will increase. As described above, it is desirable to be able to realize in the same device at the same time with a plurality of functions including a wireless key function by mounting it, for example, in the device presently used and by avoiding the use of a wireless key apparatus for exclusive use for the security system for the mobile communication terminal.